PranavLal
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Re: Sight for the Blind for <100$

Sat May 16, 2015 5:03 am

Hi all,

Tis is getting very exciting fast. The volume is the parameter I change most frequently. I have to increase it in noisy situations such as in shopping malls or when I am walking outside but decrease it when I am in an office or talking to someone.

The chest mount should work but is not optimal. We need to see things at eye-level but let us get a prototype out first and then refine.

Is it possible to make the camera selectable? I have some webcams here and a wide angle camera that I have mounted on a go pro headstrap. It is slightly above the eye but is quite usable. I may want to change cameras at some point. <smile

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seeingwithsound
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Re: Sight for the Blind for <100$

Sat May 16, 2015 2:23 pm

mikey11 wrote:2. The glasses cost me >95 Euro.
Hi Mike and Pranav,

Indeed I too recently paid 98 euros for the Technaxx TX-25 glasses, but today I searched eBay for camera glasses that look visually identical to the Technaxx TX-25 glasses but lower priced, and it looks like the following $60 glasses are a perfect match:

http://www.ebay.com/itm/HD-1080P-Sungla ... 1626907627

as well as

http://www.ebay.com/itm/5MP-HD-1080P-Vi ... 1625822699

Peter


USB Camera Glasses for the Blind
http://www.seeingwithsound.com/camera_glasses.htm

Ares
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Re: Sight for the Blind for <100$

Sat May 16, 2015 3:25 pm

Yes, they look identical from the outside. Question is, do they use the same chip/firmware/driver? My experience with this kind of device is generally "no", but the only way to find out would probably be buying them and testing. If they work out of the box, good, if they work in windows only, I could look into the driver. Otherwise, send them back if the seller gives refunds. Hardware reliability might also be a problem in any case...

Regarding shutdown of the device: Right now the raspivoice application has a "quit" menu item, which just terminates the program. I can look into recognizing a long button press to call this quit menu item. If the program is started from some kind of shell script, the script could call the system shutdown command as soon as raspivoice terminates.

A rudimentary way to control the audio volume is implemented already in the menu, it is calling the alsa mixer to set the system volume. Changing the camera input works by setting a command line option, set either to RaspiCam or USB camera. If the USB camera is chosen, any USB camera that is recognized by the system should work after rebooting without changing the settings.

PranavLal
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Re: Sight for the Blind for <100$

Sat May 16, 2015 4:14 pm

Hi Ares,
<snip
Regarding shutdown of the device: Right now the raspivoice application has a "quit" menu item, which just terminates the program. I can look into recognizing a long button press to call this quit menu item. If the program is started from some kind of shell script, the script could call the system shutdown command as soon as raspivoice terminates.
PL] That could certainly work. The idea is to have the user push a button to switch on the system and then to push a button to turn it off. There however needs to be a way of quitting the application and working at the shell prompt. This is for diagnostic purposes or if someone needs to test something. The alsa volume control should be ok for now. We can update the software later if we have to.

mikey11
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Re: Sight for the Blind for <100$

Sat May 16, 2015 5:22 pm

Just a thought...

The rotary encoder already rotates through the menu in a directional fashion.

Hypothetically one could have one direction increase the volume by 2% and the other direction decrease it by the same in addition to stepping through the menu.

Normally I would say just use a headset with a volume control, but I have one like that, and found it was too quiet still at max volume.

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seeingwithsound
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Re: Sight for the Blind for <100$

Sat May 16, 2015 8:10 pm

Ares wrote:Yes, they look identical from the outside. Question is, do they use the same chip/firmware/driver?
@Ares, if you compare the technical specifications listed for the Technaxx TX-25 at http://www.technaxx.de/download/downloa ... me=803.pdf with the data on the eBay pages then you find much more than a strong visual appearance match: e.g. 15M pixel 4480 x 3360 photo resolution, JPEG, video resolution 1440 x 1080p with 30 fps. The probability of two different chips sharing these same technical specifications for glasses with the same form factor is very low. In theory there could be one and the same chip design binned into fully functional and partially functional chips during testing at the factory, but I do not consider that likely here. I think that the Technaxx TX-25 is just a rebranded version of the exact same glasses, at a premium price. The UVC support of the Technaxx TX-25 does appear rather quirky under Windows though. Initially I got 1280 x 720 video, but the video format dialog under Microsoft Video for Windows did not list this format but only 640 x 480 and 320 x 240. Unfortunately, selecting one of these lower resolution formats gives a garbled bottom slice in the camera view, apparently because the glasses work in 640 x 360 mode when selecting 640 x 480, and 320 x 180 mode when selecting 320 x 240. The 1280 x 720 mode did not have the garbled bottom slice, but later I could not switch back to this format under Microsoft Video for Windows but only under Microsoft DirectShow (e.g. in Amcap). This does not appear to be a problem with Windows as such, because when I use another UVC compliant webcam, the Logitech C270, I can select any video format without these format mismatching issues. I also got crashes when switching between connected webcams when the Technaxx TX-25 was one of them. I suppose one will not be able to flash the Technaxx TX-25 with new/better firmware. I do not know if any of the above quirky behaviors will show up when using the glasses with the Raspberry Pi.

Peter


USB Camera Glasses for the Blind
http://www.seeingwithsound.com/camera_glasses.htm

mikey11
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Re: Sight for the Blind for <100$

Sun May 17, 2015 5:28 pm

So the bad news is my prototype speed will be even slower than anticipated.

I tried to create a single sided PCB in order to eliminate as many wires as possible. I tried pretty hard to figure out a way to make single sided work, because thats what I can produce at home. However, the available space is small, and the component density is pretty high. (using through hole components). I had no success without needing 5 or 6 jumpers. The whole point of the board is to reduce/eliminate the need to solder...

So I will have to farm this out. This means I have to learn a real PCB making software package instead of the stuff i was using before so that my output files will be compatible with the board manufacturer.

I was looking into fritzing for the schematic anyways, so I am trying to use that, and it looks like it might work, but it seems some pin definitions are not consistent from the schematic to PCB view.

On a side note, I do have my first fully functional prototype with camera module/rangefinder/vibration motor/power board/battery. I am going to wait on case design until I have the electronics board designed/tested. It seems the consensus here is that the camera module is largely irrelevant, and that glasses will be the way to go in the long run. I will keep this in mind when placing components from now on.

I look forward to Pranav's review of the cheaper glasses (to see if they are functionally identical). I tried to order the cheaper version, but somehow got blocked from doing so. Weird though, as I was able to order the expensive ones from the UK.


Have any of you guys tried to run Ares software on the pi A+? It has a really nice form factor for the cheapest version. I have only compiled on the Pi 2.

PranavLal
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Re: Sight for the Blind for <100$

Mon May 18, 2015 12:27 am

Hi Mikey11,

Could you not use a board like the Arduino Uno? That way, you are using standard components and the pin definitions should be consistent.

I should get the glasses between 28 May to 17 June and I will keep everyone posted.
Pranav

mikey11
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Re: Sight for the Blind for <100$

Mon May 18, 2015 2:33 am

Pranav,

as I am tying together items from different manufacturers, the arduino uno isn't a good solution for me. In this case, a custom board will work well.

I have been figuring out the fritzing program, and I should be able to come up with something soon. Luckily, I have looked into PCB manufacture, and there is a service in my province which can do the work, and though the price isn't fantastic for small volumes, the discounts on larger volumes justify it in the interest of reducing the soldering requirement.

This custom board should mean that when kits ship the end user will have to plug the custom board onto the rpi's 40 pin header, and then put the case together.

The plan is to do all the soldering ahead of time during manufacture to avoid blind people needing to solder to put the kit together, but still have them do assembly to gain the legal advantages of distributing a kit rather than a finished product. The custom board will accept the pin headers from the power module/rangefinder module, and these will be soldered on during manufacture. There will be pins to plug the vibration motor on and the battery will have to plug into the power module.

The assembly will consist of just a few steps, and the plugs (I believe, but am not 100% sure) are polarity independent except for 'the 40 pin header.

I would provide a detailed assembly video for this.

PranavLal
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Re: Sight for the Blind for <100$

Mon May 18, 2015 2:17 pm

Mikey11,
<snip
The plan is to do all the soldering ahead of time during manufacture to avoid blind people needing to solder to put the kit together, but still have them do assembly to gain the legal advantages of distributing a kit rather than a finished product. The custom board will accept the pin headers from the power module/rangefinder module, and these will be soldered on during manufacture. There will be pins to plug the vibration motor on and the battery will have to plug into the power module.

The assembly will consist of just a few steps, and the plugs (I believe, but am not 100% sure) are polarity independent except for 'the 40 pin header.
PL] Super and this will work nicely. As for polarity, as long as you make one side tactually different, blind people should not have a problem. Put a small notch or a bump or something else.
<snip I would provide a detailed assembly video for this.
PL] I will help convert that video to textual steps that blind people can follow. I may have to have you walk me through the steps.

johnf
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Re: Sight for the Blind for <100$

Mon May 18, 2015 3:17 pm

It is not only the advantage of low cost sight for the blind that will count.
Details like portability, parts availability, ergonomics, battery endurance...
These are what will sell the concept.
I went to LILLIPUT and bought an ODROID C with camera and USB soundcard and basic Android 4.2.
I can now demonstrate a neat, pocket sized vOICe setup which NEARLY delivers the service.
The control interface uses the generic IR hand control plus the BT keyboard. .Not convenient but fairly hackable as a sequenced codetrain device.
The soundcard has a level problem.
The normal speed output stutters.
However......
The reaction from would-be "customers" has been enormously favourable. They like the wearability and sourceability and the fact that an attainable small format can be demonstrated. People are confident that next year`s chips will deal with this year`s problems.
The days of the knapsack are numbered.
Keep it up.

mikey11
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Re: Sight for the Blind for <100$

Mon May 18, 2015 6:09 pm

I've been using the raspberry pi 2 with the software, and it definitely delivers.

Smart use of the rotary encoder is keeping parts count low, and today I've placed the order for my first revision of the circuit board (turns out with a bit of coaxing that fritzing is actually a top notch program.

If the circuit board is successful, things will continue to move along quickly.

Also, when it comes to the circuit board, I have some unused real estate because I basically made something like a pi-hat/pi-plate.

I have already considered adding a few things to the board:

1. A timed shutdown circuit to totally cut power after a soft shutdown.
2. filter components for the rotary encoder (hardware debounce)
3. Protection features for power delivery. (I am going to deliver power over the 5V GPIO pins, but then I don't have a fuse and diode inline like the power supply from the usb port normally does.

These are not required to make functional and reliable prototypes, and will be considered more later.

mikey11
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Re: Sight for the Blind for <100$

Wed May 20, 2015 2:11 am

so I am currently waiting on parts:

1. PCB's should be on the way. I have two of them in under a week
2. glasses: I have ordered both the more expensive and less expensive versions of the the tx25's I expect receipt in early to mid june for both.

When I get the PCB's I will make two prototypes and test. If all goes well I will order 8 more PCB's and finish the same number of prototypes.

During that time I will have enough for 4 complete prototypes, and have to place an order to make the last 6.

If the PCB checks out, I will ship kits to Pranav, Peter, and Ares. (If you are interested in getting one, please PM me your shipping details). If you want to save me $$ indicate if you have a Pi Version 2 available.

In order to ship, I will also have to finish a case model. I am waiting to do this once I get the PCB's because there will be component height and width considerations to iron out. I can't make the case models until I have the electronics assembled.

Due to random purchases of batteries, your can expect anywhere between 1700 - 6600 mAh batteries.

Case design is now a consideration on other levels:

I could make a case that mimics a real world item, or make the case a symbol in itself. The case is still to be a chest level item to let the rangefinder work. So far the best idea passed my way is to make the case resemble a day to day item, such as a case for glasses.

Any additional ideas are welcome.

PranavLal
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Re: Sight for the Blind for <100$

Wed May 20, 2015 11:50 pm

Hi Mikey11,

How big is the setup going to be? For example, is it going to be as big as a smart phone? The case needs to be easy to carry and I would base my design on that. Flat may work best but from what I have heard, phone manufacturors are going for curved devices so I do not know what shape is best. As for the range finder, can't we mount that on the glasses?

Pranav

mikey11
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Re: Sight for the Blind for <100$

Thu May 21, 2015 10:27 pm

Well, given that there will be parts that require more space than a smartphone, I can't make it much smaller. I think it will be manageable.

At the moment I am targeting something similar to 100mm length X 70mm width X 30mm depth. The blackberry passport is only better in terms of depth. So I believe this design is treading down the right path.

This looks like it will be the smallest size possible given thermal considerations. I have ordered some heat sinks to do some higher temperature testing to help simulate performance in India.

The rangefinder could be relocated, but it will be mounted in the box for the prototypes. For your prototype, I will see if I can lengthen the wires for a head mount. I'm not sure if this will be possible with the rangefinder I've chosen, there may be consideration required for transmitting the 3v signal over longer distances.

The good news is that removing the camera module allows for a more compact design. I will consult with the rangefinder company to get some clarity on that. Removing the rangefinder from the enclosure for headmount will also allow for a slightly more compact case.

During my testing of the rangefinder, I varied the vibration motor level with distances between 5 meters and 1 meter going from 10% output to 100% output at 1 Meter. Distances under 1 Meter caused an alarm mode where the vibration turns on and off rapidly to indicate a possible collision.

In the interests of battery life, I want to rethink this behaviour. If I were to make the motor give a number of pulses indicating how many meters to the nearest object, and then had 100% vibration within 1 meter it would use much less power over time.

I know you have used rangefinders in the past, but I was not sure what kind of feedback they gave you. What do you think about the above?
Last edited by mikey11 on Thu May 21, 2015 11:03 pm, edited 1 time in total.

mikey11
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Re: Sight for the Blind for <100$

Thu May 21, 2015 11:02 pm

regarding the dimensions. You can fully expect that one of those will be increased by 10mm, most likely the depth. This will most likely come from considerations over heat generation.

PranavLal
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Re: Sight for the Blind for <100$

Fri May 22, 2015 12:06 am

Hi Mikey11,
<snip
In the interests of battery life, I want to rethink this behaviour. If I were to make the motor give a number of pulses indicating how many meters to the nearest object, and then had 100% vibration within 1 meter it would use much less power over time.
PL] This should work. There is a ultrasonic smartcane that I use which you can read about at
http://smartcane.saksham.org.

It uses pulses and I as well as other blind people am able to handle those without problems.

Pranav

mikey11
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Re: Sight for the Blind for <100$

Fri May 22, 2015 5:46 am

I did a little reconfiguring in the existing case I printed:

http://imgur.com/EKpV2hS

You can see the vibration motor stuck to one side with adhesive. Eventually the case model will have a pocket built in to accomodate the motor.

By removing the camera module, I was able to place the battery inside the case. Currently the only part outside the case is the power module.

As you can see from the open view, lots of wires. These will all be gone soon. The custom PCB's should be arriving any day now.

http://imgur.com/r0HbqUZ

The ability to pack it all in except the power module strongly suggests the final size won't be much larger.

PranavLal
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Re: Sight for the Blind for <100$

Sat May 23, 2015 2:07 am

Hi Mikey11,
I could not resist and had a look at
http://imgur.com/EKpV2hS

I can see the wires. What is the structure that has a mesh like texture on the right? Is that for heat discipation?

You could, in theory have a 2 module design in a single case but that is going to get unwieldy. See if you can find pictures of the KNFB Reader classic. There were 2 physical modules but in a single soft case. I am in 2 minds about putting the battery in the case. Yes, it is a good idea but what if someone wants to put in a bigger battery? Can I connect an external battery pack to the power module? I may not need this in regular use but the day I go exploring, I may want extra power backup.

By the way, what can I control on the go with the current implementation? Do I have speed and volume control?
Pranav

mikey11
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Re: Sight for the Blind for <100$

Sat May 23, 2015 3:40 am

The assembly on the right with the wires attached is the power module. It is the only thing that didn't fit in the first case model I chose.

As it stands, the power module is fantastic. It lets the pi be powered by the internal battery, AND lets you plug in an external battery. The module then uses the external battery to recharge the internal one while maintaining a constant output.

Therefore, when you plug in an external battery it just adds the capacity together (with some minor losses along the way).

As such, an external battery could easily put you over 24 hours when combined with the internal battery based on estimates.

This assumes an external battery with a capacity of 9000 mAh, and an internal of 2000 mAh.

Currently speed and volume control are not enabled.

I am not 100% sure about accessing the GPIO from two processes at the same time, and I would rather have the C code that Ares made perform those functions.

I will explore doing both of those from the rangefinder.py code I submitted recently. I know from investigation that changing the speed of input ( frames of video converted per second) is a command line function from Ares code. The volume falls under a slightly different category, and may be more easily accessible domain for me.

Given Ares quick responses in the past, I will hope, but I will also work on it from the rangefinder code in python on both accounts.

I expect my PCB's tommorrow, and expect all fronts to proceed rapidly from there.

PranavLal
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Re: Sight for the Blind for <100$

Sat May 23, 2015 6:02 am

Hi Mikey11,
As regards the volume, don't let that slow things down. I could use a headset with a volume control or is there a way to invoke the alsa mixer on the fly? The speed is required if the user wants to track fast moving objects. If I walk fast, I often switch the vOICe to double speed.

Pranav

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seeingwithsound
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Re: Sight for the Blind for <100$

Sat May 23, 2015 7:40 am

This neural network based object recognition app may at some point make an interesting talking visual guide add-on for The vOICe on Raspberry Pi? The Raspberry Pi is mentioned in the post,

https://plus.google.com/+EugenioCulurci ... hbQbpKr8gB

reading "runs great on Odroid C1, U3, XU3, and most linux embedded with some juice, like Rasperry Pi 2". More at

https://github.com/teradeep/demo-apps

reading "It has been trained to recognize most typical home indoor/outdoor objects in our daily life". Demo videos at

https://www.youtube.com/watch?v=_wXHR-lad-Q
https://www.youtube.com/watch?v=B0TreumQO-0

Peter


The vOICe for Android
http://www.seeingwithsound.com/android.htm

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seeingwithsound
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Re: Sight for the Blind for <100$

Sat May 23, 2015 11:01 am

Today I received my new Android TV stick, a Rikomagic MK802 IV, and installed The vOICe for Android on it. I then managed to get it to work with the UVC compliant Technaxx TX-25 camera glasses that we discussed here in the context of Raspberry Pi, after *disabling* The vOICe for Android's own UVC support in its Other Settings menu. However, under Android too, just as under Microsoft Windows, I observed a garbled bottom slice in the live camera view, so it looks like this is really an issue with the UVC driver in the glasses and not some Windows issue with UVC compliance. Have people who tried the Technaxx TX-25 camera glasses with the Raspberry Pi also observed a garbled bottom slice in the camera view?

On Windows I found that this problem showed at 320 x 240 and 640 x 480 resolutions, but not at 1280 x 720 resolution. For the Windows version of The vOICe I created a registry hack to force the glasses into 1280 x 720 mode, but for the Android version of The vOICe I still need to look into the possibilities with these apparently rather quirky UVC camera glasses.

Peter


The vOICe for Android
http://www.seeingwithsound.com/android.htm

mikey11
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Re: Sight for the Blind for <100$

Sun May 24, 2015 1:45 am

I hope the issues with the glasses can be sorted out without jeopardizing the computational speed.

That object recognition utility looks fantastic. I imagine that getting it to espeak the object names at double speed would be possible, but maybe not at the same time as running the vOICe routines.

It's definitely a continuous improvement item to take note of for the future though.

I could easily see how if you could toggle between the vOICe and that program, it would be extremely helpful.

A sad note: I got my first PCB's. Unfortunately, I have traces crossing pads at the wrong points in numerous places on the board. I think I may be forced to manually route portions of the traces to fix these issues, but it shouldn't be impossible. The design was fine, but the pad width caused the real item to differ from the designed item.

Live and learn I guess. It was my first stab at fritzing and gerber file output, and also my first experience with the PCB supplier. I already fixed the problem in the design, and will submit it for round two soon. I'm just considering adding a hard power off circuit to completely cut power to the pi after a soft shutdown has been achieved. Hopefully in an automated fashion.

Good news though is that all the components fit nicely in the current PCB design.

I am looking at installing a momentary pushbutton to turn the pi on. I haven't totally figured this out yet.

I'm hoping Ares will turn the speed into a menu item, and I think the volume should be handled as I suggested:
Each time the encoder increases the volume goes up 2%
Each time the encoder decreases the volume goes down 10%
This will also cycle through the menu items, which is sort of annoying, but completely avoids additional hardware and circuitry. The reason for the different % changes is to allow fine tuning of the volume as it comes up, but quick turn down if a situation warrants it.

I will investigate these issues as time permits, but my focus right now is on successful PCB production and implementation followed by case design.

If the hardware is done, Software can follow, and correct behaviours via software updates after the devices are in beta testers hands.

mikey11
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Re: Sight for the Blind for <100$

Sun May 24, 2015 2:07 am

I have been looking into what happens when the pi powers down, and it appears that after a soft shutdown, there is still power sent to the USB ports.

Assuming a person disconnected any USB peripherals such as the camera glasses, then I shouldn't need to create a timed shutdown circuit, and can still install a momentary pushbutton switch that interacts with the convenient two pin header for reset that is on the pi board already.

This way, I can integrate the pushbutton onto the PCB, and away we go. Easy Easy. No need for timer circuits and additional power management crap.

This is what I am going to pursue in the near future. If this turns out to be a bad idea, I'm sure I will find out.

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